We've released our sharks

The large ragged-tooth sharks that you are familiar with are no longer at the Two Oceans Aquarium - they have been released back into the wild. The I&J Predator Exhibit has been closed down for renovations and upgrades. We know you love sharks, and so do we, and that's why we're hard at work creating a brand new, dedicated shark exhibit.

In the meantime, we've opened the I&J Ocean Exhibit - a mesmerising look into warmer waters - where we have three turles, a guitar shark, rays, yellowfin tuna, striped bonito, and so much more. Or check out the new Jelly Gallery, with its surprises big and small. And we do still have ragged-tooth sharks: juvenile ones, in the Atlantic Ocean Gallery.

Releasing the sharks

On 23 May, we removed two raggies from the I&J Predator Exhibit, and they were released offshore near Mossel Bay the very next day. Then, during the week starting 30 May we removed and released the two sharks that remained in the I&J Predator Exhibit.

This was all in preparation for the closing of the I&J Predator Exhibit for repairs in mid-June, and the long-awaited opening of the new large-scale exhibit around the same time. Once the repairs are completed – upgrades could take up to 18 months – the old predator exhibit space will re-open as a dedicated shark exhibit with a brand new name.

Shark science

The ragged-tooth sharks have all been tagged with internal VEMCO multi-purpose transmitters. These transmitters have a 10-year battery-lifespan and will transmit to various acoustic monitoring receivers that are dotted along the southern African coast.

“As with all our previous shark releases, we are really excited as we will receive data from these transmitters for the next 10 years and through that will continue to contribute to the scientific research being conducted on sharks around the southern African coast,” said Two Oceans Aquarium Operations Manager Tinus Beukes.

Photo courtesy Ruvan Boshoff/Sunday Times

To move sharks requires team effort and patience. Trained Aquarium divers manoeuvre each shark into a transparent PVC cone. Once secured, the shark is moved to a holding tank that has been placed into the exhibit. From there, the sharks are moved to a 6 000 litre holding tank on the back of a transport truck.

The truck and tank are fitted with life support systems that maintain water quality during the journey to Mossel Bay, and overnight. Then, the next morning, the sharks are transported to the harbour, transferred to a boat and taken out to an offshore reef for release.

We regularly tag and release ragged-tooth sharks

In 2004, the Two Oceans Aquarium in conjunction with Save our Seas and the AfriOceans Conservation Alliance (AOCA), tagged and released Maxine, a ragged-tooth shark that had been housed in the Aquarium for eight and a half years. Maxine’s fascinating history [PDF] and release gave rise to the M-Sea programme (Maxine Science, Education and Awareness Programme).

This programme aimed to gain scientific information about ragged-tooth sharks and to raise awareness of their plight.

Since then, the Two Oceans Aquarium has subsequently released several other sharks back into the ocean.

Kay, a female ragged-tooth shark, was released by us in April 2013. Photo by Steven Benjamin/Animal Ocean

Why do we release our sharks?

Scientists are using every opportunity available to learn more about these incredible animals that have been roaming the earth’s oceans for more than 400 million years. Releasing sharks that have been housed at the Two Oceans Aquarium affords us a great opportunity to study ragged-tooth sharks in general and their migration patterns along the southern African coastline. The data from Maxine’s tag and other tagged sharks revealed fascinating aspects of the sharks’ lives.

To learn more about our research and conservation work with sharks, click here.